1. Field of the Invention
The present invention relates to a micro camera module with a lens and a built-in CCD or CMOS sensor and a method for manufacturing the camera module.
2. Description of the Related Art
Micro camera modules usually have, for example, an image pickup sensor, an infrared (IR) cut filter, a substrate, passive parts, an optical lens, and a diaphragm.
In recent years, growing desires have been made to reduce the size of camera modules. The following are important in reducing the size of camera modules.    (1) Reduction in the sizes of a sensor chip and passive parts used    (2) Reduction in the size of pixels for the sensor and in the thickness of an optical system
(1) is mainly a reduction in lateral size which can be achieved by improving parts and mounting techniques. In particular, much attention has been paid to a mounting technique using a substrate of the same size as that of the sensor chip, for example, a chip scale package (CSP). On the other hand, (2) is mainly a reduction in vertical size. Normally, optical parts such as an IR cut filter, a diaphragm, and an optical lens need to be stacked on the sensor. This makes it difficult to reduce the thickness.
Jpn. Pat. Appln. KOKAI Publication No. 2001-238103 discloses an image pickup device serving as a camera module. This image pickup device has an image pickup element provided on a substrate and on which an optical element having a coupling lens portion is provided. The image pickup element and the substrate are electrically connected together via wire. The substrate is further sealed with resin so as to expose the coupling lens portion to integrate the substrate, image pickup element, and optical element together.
However, the conventional camera module requires a lens barrel and holder which support the lens, a holder that supports the IR cut filter, a housing that holds the substrate, image pickup element, and optical element, a sealing resin that seals the stack, and the like. Further, the lens barrel and holder, the holder supporting the IR cut filter, the substrate, the image pickup element, and the optical element are separate parts. These parts are very small and difficult to assemble. Furthermore, if these parts are assembled, their sizes and thicknesses cannot be easily reduced to required values. Therefore, it has been desirable to provide a high-performance camera of a reduced size and reduced thickness and a method for manufacturing such a camera.